Investigation of spectroscopic properties and thermal stability of Er3+/Yb3+-co-doped Bi2O3–B2O3–Ga2O3 glasses

A series of Er3+/Yb3+-co-doped 60Bi2O3–(40−x) B2O3 –xGa2O3 (BBGA x=0, 4, 8, 12, 16 mol%) glasses have been prepared. The absorption spectra, emission spectra, fluorescence lifetime of Er3+:4I13/2 level and thermal stability were measured and investigated. Three Judd–Ofelt intensity parameters Ωt (t=2,4,6) (Ω2=(4.67–5.93)×10−20 cm2, Ω4=(1.50–1.81)×10−20 cm2, Ω6=(0.92–1.17)×10−20 cm2) of Er3+ ions were calculated by Judd–Ofelt theory. It is found that the Ω6 first increases with the increase of Ga2O3 content from 0 to 8 mol% and then decreases, which is mainly affected by the number of non-bridging oxygen ions of the glass network. The high peak of stimulated emission cross-section (σepeak=0.83-1.03×10-20cm2) of Er3+: 4I13/2→4I15/2 transition were obtained according to McCumber theory and broad full width at half maximum (FWHM=69–76 nm) of the 4I13/2→4I15/2 transition of Er3+ ions were measured. The results indicate that these new BBGA glasses can be used as a candidate host material for potential broadband optical amplifiers.